docs: raw fetch --html record and kb/CONTRACT.md path budget follow the folder accept (#112)

Files changed:
- CHANGES.md
- VERSION
- kb/CONTRACT.md
- tools/CONTRACT.md
- tools/chemenu/commands/raw_cmd.py

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

tools/chemenu/commands/raw_cmd.py

@@ -1229,9 +1229,10 @@ def _fetch_html_file(html: Path, source_url: Optional[str]) -> None:
         ),
         cli_contract.Failure(
             label="raw fetch --html",
-            cause="`--url` is missing, the file is not under `incoming/` or does not exist, or "
-            "`incoming/<stem>.md` already exists",
-            reaction="Fix the named argument and retry once - nothing was written",
+            cause="`--url` is missing, the file is not directly in `incoming/` or does not "
+            "exist, or `incoming/<stem>.md` already exists",
+            reaction="Fix the named argument and retry once - nothing was written. A saved page "
+            "inside a subdirectory of `incoming/` is moved up into `incoming/` first",
         ),
     ),
     examples=(